The field of the invention relates generally to in-flight refueling drogues, and more specifically, to a method and system for an air-refueling drogue that provides positive latch indication of a refueling probe, reduced force latching/detaching, measurement of hose tension at the drogue end instead of at the reel end, and transmission of hose tension measurement and positive latch indication to the hose reel control system.
Current probe and drogue aerial refueling systems infer coupling of the receiver aircraft probe with the tanker aircraft drogue on the basis of measurement of a hose tension decrease when the receiver aircraft pushes on the drogue with the refueling probe. At least two known categories of prior attempts to solve the problem, both use measurements taken at the hose reel. One method uses detection of an imbalance in hydraulic pressure to infer coupling of the receiver. Another method uses a load cell to measure a change in hose tension and infer coupling. Both of these methods are subject to false indications caused by friction as well as aerodynamic and receiver aircraft induced forces that cause false inference of coupling. Such methods are used because power, including electrical, hydraulic, pneumatic power, is not available at the drogue to allow additional remote sensing to give positive indication and control of coupling. Batteries could be used, however batteries have capacity, heating, charging, and power life aspects to contend with. The other approach is to incorporate wires or optical fibers, or the like, in the aerial refueling hose. Both of these are undesirable from an operational complexity, durability, cost, and safety view.